exam3physiological Flashcards
Sensory receptor
A specialized neuron that detects a particular category of pysical events
Sensory transduction
the process by which sensory stimuli are transduced into slow, graded receptor potentials
Receptor potential
a slow, graded electrical potential produced by a receptor cell in response to a physical stimulus
What is the range of the visible light spectrum
380nm (violet)- 760nm (red)
What are the three dimensions of perceived color and their corresponding physcial dimensions?
Hue (wavelength); Saturation (purity of the light); brightness (intensity)
Saccadic movement
the rapid, jerky movement of the eyes used in scanning a visual scene
Pursuity movement
the movement that the eyes make to maintain an image of a moving object on the fovea
Orbits
bony pockets in the fornt of the skull where the eyes are suspended
sclera
tough, white outer coat of the eye that is opaque and prevents entry of light into the eye
conjunctiva
mucous membranes that line the eyelid and fold back to attach to the eye
The anatomy as light travels through the eye
cornea, iris/pupil, lens/ciliary muscles, vitreous humor,retina
ciliary muscles
the muscle fibers that attach to the outer edge of the lens and changes its shape; used for accomodation
accomodation
changes in the thickness of the lens of the eye, accomplished by the ciliary muscles, that focus images of near or distant objects on the retina
vitreous humor
a clear gelatinous substance inside the eye
retina
the neural tissue and photoreceptive cells located on the inner surface of the posterior portion of the eye
rods
one of the recepotr cells of the retina; sensitive to light of low intensity
cones
one of the recepotr cells of the retina; maximally sensitive to one of three different wavelengths of light and hence encodes color vision
photoreceptor
one of the receptor cells of the retina; transduces photic energy into electrical potentials
fovea
the region of the retina that mediates the most acute vision of birds and higher mammals. Color-sensitive cones constitute the only type of photoreceptor found in the fovea
optic disk
the location of the exit point form the retina of the fibers of he ganglion cells that form the optic nerve; responsible for the blind spot
bipolar cell
a bipolar neuron located in the middle layer of the retina, conveying information from the photoreceptors to the ganglion cells
horizontal cell
a neuron in the retina that interconnects adjacent photoreceptors and the outer processes of the bipolar cells
amacrine cell
a neuron in the retina that interconnects adjacent ganglion cells and the inner processes of the bipolar cells
lamella
a layer of membrane containing photopigments; found in rods and cones of the retina
photopigment
a protein dye bonded to retinal, a substance derived from vitamin A; responsible for transduction of visual information
opsin
a class of protein that, together with retinal, constitutes the photopigments
retinal
a chemical synthesized from vitamin A; joins with an opsin to form a photopigment
rhodopsin
a particular opsin found in rods; consists of rod opsin and retinal; splits apart when exposed to light
dorsal lateral geniculate nucleus
a group of cell bodies within the lateral geniculate body of the thalamus; receives inputs from the retina and projects to the primary visual cortex
magnocellular layer
one of the inner two layers of neurons in the dorsal lateral geniculate nucleus of the thalamus; transmits information necssary for the perception of form, movement, depth, and small differnces in brightness to the primary visual cortex
parvocellular layer
one of the four outer layers of neurons in the dorsal lateral geniculate nucleus; transmits information necessary for perception of (red and green cones) color and fine details to the primary visual cortex
koniocellular sublayer
one of the sublayerso f neurons in the dorsal lateral genicualte nucleus found ventral to each of the magnocellular and parvocellular layers; transmits information from short-wavelength (“blue”) cones to the priamry visual cortex
retinal disparity
the fact that points on objects located at different distances from the observer will fall on slightly different locations on the two retinas; provides the basis for stereopsis
cytochrome oxidase blobs
the central region of a module of the prmary visual cortex, revealed by a stain for cytochrome oxidase; contains wavelength-sensitive neurons; part of the parvocellular system
what features of a visual stimulus does the striate cortex respond to?
orientation (simple, complex, and hypercomplex cells), movement, spatial frequency (sine-wave grating and spatial frequency), retinal disparity, color (cytochrome oxidase blobs)
extrastriate cortex
a region of the visual association cortex; receives fibers from the striate cortex and from the superior colliculi and projects to the inferior temporal cortex
dorsal stream
a system of interconnected regions of visual cortex involved in the perception of spatial location, beginning with the striate cortex and ending with the posterior parietal cortex; recognizes where the object is and speed and direction of movement
ventral stream
a system of interconnected regions of visual cortex involved in the perception of form, beginning with the striate cortex and ending with the inferior temporal cortex; recognizes what an object is
V4
analysis of form in interglob regions; processing of color constancy; glob regions associated with color processing
V8
found in lateral occipital complex; color perception and color memories
cerebral achromatopsia
inability to discriminate among different hues; caused by damage to area v8 of the visual association cortex
visual agnosia
deficits in visual form perception in the absence of blindness; caused by brain damage to the ventral stream of the visual association cortex
lateral occipital complex
a region of the extrastriate cortex, involved in perception of objects other than people’s bodies and faces
fusiform face area
a region of the visual association cortex located in the inferior temporal area; involved in perception of faces; when damaged results in prosopagnosia
extrastriate body area
a region of the visual association cortex located in the lateral occipitotemporal cortex; involved in perception of the human body and body parts other than faces
parahippocampal place area
a region of the medial temporal cortex; involved in perception of particular places
V5 or medial temporal
perception of moving stimuli;
V5a or medial superior temporal
responds to complex patters of movement like radial, circular, or spiral motion
dorsolateral medial superior temporal (MSTd)
perception of optic flow (complex motion of points in the isual field caused by relative movmenet between the oberver and environment)
akinetopsia
inability to perceive movement, caused by damage to area v5 (MST) of the visual association cortex
intraparietal suclus
the end of the dorsal stream of the visual association cortex; involved in perception of location, visual attention, and control of eye and hand movements
what is the range of perceivable sounds for humans?
30-20,000 vibrations per second
What are the three physical dimensions and corresponding perceptual dimensions of sound?
pitch and frequency; loudness and amplitude; timbre and complexity
hertz
cycles per second
anatomical steps of the auditory system
pinna, ear canal, tympanic membrane, malleus, incus, stapes, oval window, vestibule, cochlea, auditory nerve, round window
anatomical parts of the cochlea
scala vestibuli, scala media, scala tympani; organ of corti (vasilar membrane, outer hair cells, deiters’s cells, inner hair cells, cilia of hair cells, tectorial membrane, axons of auditory nerve
deiters’s cell
a supporting cell found in the organ of corti; sustains the auditory hair cells
cilium
a hairlike appendage of a cell involved in movement or in transducing sensory information; found on the receptors in the auditory and vestibular system
tip link
an elastic filament that attaches the tip of one cilium to the side of the adjacent cilium
insertional plaque
the point of attachment of a tip link to a cilium
nerve pathway for auditory information
auditory nerve, ventral cochlear nucleus or dorsal cochlear nucleus in the medulla, superior olivary complex of the opposite side of the medulla, lateral lemniscus, inferior colliculus, medial geniculate nucleus, auditory cortex of the temporal lobe
cochlear nucleus
one of a group of nuclei in the medulla that receive audtitory information from the cochlea
superior olivary complex
a group of nuclei in the medulla; involved with auditory functions, including localization of the source of sounds
lateral lemniscus
a band of fibers running rostrally through the medulla and pons; carries fibers of the auditory system
tonotopic representation
a topographically organized mapping of different frequencies of sound that are represented in a particular region of the brain
place code
the system by which information about moderate to high frequencies is coded by different locations on the basilar membrane; higher frequencies closer to stapes- lower frequencies at the end; outer hair cells contract to amplify the vibrations of the basilar membranes and enhance the signal received by the inner hair cells
rate coding
the system by which information about different frequencies is coded by the rate of firing of neurons in the auditory system; used for frequencies lower than 200 Hz
fundamental frequency
the lowest and usually most intense, frequency of a complex sound; most often perceived as the sound’s basic pitch
overtone
the frequency of complex tones that occurs at multiples of the fundamental frequency
methods of localization for auditory system
detection of different arrival times to each ear by the superior olivary complex of the medulla; for continuous low-pitched sounds use phase differences; sonic shadow is used for high-pitched continuous frequencies (ear closest receives most intense stimulation; analysis of timbre using pinna
vestibular sac
one of a set of two receptor organs in each inner ear that detects changes in the tilt of the head
Semicircular canal
one of the three ringlike structures of the vestibular apparatus that detect changes in read rotation.
Utricle
one of the vestibular sacs; receptive tissue is located on the floor; otoconia shifts against the cilia of the hair cell embedded in the filamentous base upon which the otoconia rests
Saccule
one of the vestibular sacs; receptive tissue is located on the walls; otoconia shifts against the cilia of the hair cell embedded in the filamentous base upon which the otoconia rests
Ampulla
an enlargement in a semicrcular canal; contains the cupula and the crista
Cupula
a gelatinous mass found in the ampulla of the semicircular canals; moves in response to the flow of the fluid in the canals
vestibular ganglion
a nodule on the vestibular nerve that contains the cell bodies of the bipolar neurons that convey vestibular information to the brain
cutaneous sense
one of the somatosenses; includes sensitivity to stimuli that involve the skin (pressure, vibration, heating, cooling, and events that cause tissue damage/pain)
proprioception
perception of the body’s position and posture
kinesthesia
perception of the body’s own movements
organic sense
a sense modality that arises from receptors located within the inner organs of the body
glabrous skin
skin that does not contain hair; found on the palms and the soles of the feet; contain meissner’s corpuscles and merkel’s disks
ruffini corpuscle
a vibration-sensitive organ in hair skin; responds to indentations of the skin
pacinian corpuscle
a specialized, encapsulated somatosensory nerve ending that detects mechanical stimuli, especially rapid vibrations
Meissner’s corpuscle
the touch-sensitive end organs located in the papillae, small elevations of the dermis that project up into the epidermis
what is the somatosensory pathway for precise touch and kinesthesia?
dorsal root ganglion, dorsal columns, nuclei of the dorsal columns, medial lemniscus, ventral posterior nucleus of thalamus, primary somatosensory cortex
what is the somatosensory pathway for pain and temperature?
dorsal root ganglion, spinothalamic tract, medial lemniscus, ventral posterior nucleus of thalamus, primary somatosensory cortex
olfactory epithelium
the epithelial tissue of the nasal sinus that covers the cribriform plate; contains the cilia of the olfactory receptors
olfactry bulb
the protrusion at the end of the olfactory tract; receives input from the olfactory receptors
mitral cell
a neuron located in the olfactory bulb that receives information from olfactory receptors; axons of mitral cells bring information to the rest of the brain
olfactory glomerulus
a bundle of dendrites of mitral cells and the assoicated terminal buttons of the axons of olfactory receptors
